Update js/bootstrap-fileupload.js

This addresses Issue #55, #62
https://github.com/jasny/bootstrap/issues/55
https://github.com/jasny/bootstrap/issues/62

Support for jquery.browser was removed in 1.9. This caused the "Remove" button to not work. 

Changed line 103 from 
   if($.browser.msie){
to 
   if (navigator.userAgent.match(/msie/i)){